ABSTRACT The peat water is high in organic substance, color and Fe. One alternative of peat water treatments is coagulation with natural coagulant. This study aims to the removal of organic matter, color and iron by using corn flour. Corn seeds were prepared by drying naturally under sunshine for 1 day and sieving with a 100 mesh filter size. The study used 20 mg/L; 40 mg/L; 60 mg/L; 80 mg…